Screw driver



June 23, 1942. s Qw r 2,287,457

SCREW DRIVER Filed July 2, 1940 Jr W50 II IIIIJ I 4 gwua/wfowl AUsT/N L.STOWELL FZPEDEZPZCK A. VOLZ Patented June 23, 1942 SCREW DRIVER.

Austin L. Stowell and Frederick A. Volz, New Brit-.

ain, 001111., assignors to The Stanl ey Works,

New Britain, 001111., a corporation of Connecticut Application July 2,1940, Serial No. 343,540

" 2 Claims. (01. 219-102) This invention relates to improvements inscrew drivers and more particularly to a screw driver comprising ahandle or tool holder adapted to receive removable bits.

An object of the invention is to provide a screw driver of theabove-indicated type having various features of novelty and advantageand which is particularly characterized by its extreme simplicity inconstruction, economy of manufacture, and efficiency of operation.

Other objects will be in part obvious and in part pointed out more indetail hereinafter.

The invention accordingly consists in the features of construction,combination of elements, and arrangement of parts which will beexemplifled in the construction hereafter set forth and the scope of theapplication of which will be indicated in the appended claims.

In the accompanying drawing:

Figure 1 is a perspective view of a screw driver embodying the inventionherein;

Fig. 2 is an enlarged fragmentary view partly in section of the deviceillustrated in Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2; and

Fig. 4 is a view taken on the line 4-4 of Fig. 1.

Referring to the drawing, the invention is shown as embodied in a screwdriver comprising a tool holder A and removable bit 3. In accordancewith the invention herein, the bit holder and bit are provided withcooperating wedging means adapted to frictionally engage one another tofirmly secure the bit within the tool holder; the wedging means of thebit holder being integral therewith and formed or struck from the metalof the holder.

As shown in the drawing, the bit holder A comprises a shank E2 of anysuitable metal having fixed on one end thereof the usual gripping thesocket, is depressed radially and on a taper towards the inner endthereof to provide a pair of internal longitudinally extending indentsI9 spaced apart by a raised central portion 20.

As clearly seen in Fig. 3, the indents provide centrally facing wedgingshoulders 22 arranged on a normal chord intersecting the innercircumference of the socket and integral therewith,

and the excess metal of the socket being taken up by the centrallyraised portion 20. Likewise, the vertical distance from the shoulders 22to a diameter parallel thereto gradually diminishes from the outer edgeof the shoulders to the inner end, thus providing a gradually taperedwedge adapted to cooperate with a cooperating wedging surface on the bitover a relatively large gripping area.

The bit B is provided with a cylindrical shank 26 having an outercircumference so related to the inner circumference of the socket thatit makes a relatively close fit therewith when the bit is positionedtherein. The shank 26 also has a portion cut away for a substantiallength thereof to provide a wedge 28 having a flat wedging surface 30adapted to cooperatively engage the wedging shoulders 22 of the socket.

In order to assure a surface engagement over the entire area of theshoulders, the flat wedging surface 30 of the shank bit also defines anormal chord intersecting the circumference of the wedge and having aprogressive taper corresponding to that of the wedging shoulders 22.

With this arrangement, when the bit is placed within the socket, theflat wedging surface 30 thereof will frictionally engage the wedgingshoulders 22 of the socket and thus securely hold the bit within thesocket. Moreover, as the wedging shoulders 22 of the sockets are spacedto either side of the center line of thewedging surface 30 of the bit,no relative turning movement will occur between the bit and handle whenthe tool is in use. With the foregoing construction, the tool isparticularly adaptable for use in industrial work where, for example, asin the assembly of automobile bodies, the bits of the screw driver willrapidly wear. As is apparent, as soon as one bit wears, by simplytapping the socket the bit ma be loosened and dropped out and anotherhit readily placed therein.

Although the invention has been shown and described with particularreference to a screw driver, it is obvious that the tool holder could beutilized for gimlets, bits, chisels, and any similar tools.

As many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the followingclaims is intended to cover all of the generic and specific features ofthe invention herein described and all statements of the scope of theinvention which, as a matter at language, might be said to falltherebetween.

We claim as our invention:

1. A tool holder of the character described, having a socket providedwith a longitudinally extending cylindrical bore open at one end, the

spams? inwardly intermediate the ends thereof and on a taper towards theend of the socket, said indentations being relatively short compared tothe length of the socket to provide within the bore a pair of spacedapart integral longitudiouter surface 01 said socket being indented in-10*nal1y extending wedging shoulders tapering towardly to provide theinner surface of said socket with a pair of spaced apart integrallongitudinally extending chordal wedging shoulders intermediate oi theends of the socket and tapering towards the closed end of the socket,and a re movable tool receivable within said socket and having a flatface provided with a corresponding taper in said socket shoulders andadapted to irictionally engage same to retain same within the bore.

wards the closed end of the socket, and a removable tool receivablewithin said socket and having an elongated flat iace approximating thelength of the socket and provided with a correspending taper to saidsocket shoulders and adapted to i'rietionally engage same to retain saidtool within the bore and prevent relative turning movement of the socketand tool.

AUSTIN L. STOWELL. FREDERICK A. VOLZ.

